This book is ____________.[ ]
A. Tom
B. Toms
C. Tom's
答案:C
After working until midnight for two weeks, he finally ______ and had to stay in the hospital.
A.broke up
B.gave in
C.broke down
D.gave up
图A表示某哺乳动物(基因型为EeRrDd)的一个器官中一些处于分裂状态的细胞图像,图B表示相关过程中细胞核内DNA含量变化曲线示意图。请据图回答:
某种抗癌药物能专一性地与DNA聚合酶发生不可逆结合。实验动物服用该种抗癌药物后其癌细胞将在图B中的()段受阻